Controlling a transmission with segmented wheels by means of electronic control elements

ABSTRACT

The control device is for controlling a transmission ratio between a traction means and a wheel set rotatable about a wheel axle and including at least two wheel blades alternatively wrapped around by the traction means. At least one of the wheel blades is composed of several independently adjustable wheel rim segments. The adjustment of the wheel rim segments in relation to a fixed plane (“plane of alignment”) in which the traction means wraps around the wheel set is effected by the control device in a direction substantially transverse to the plane of alignment. The control device includes at least one electrically actuatable control element, in particular a servomotor, provided that the at least one control element is arranged to rotate with the at least two wheel blades.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a U.S. national phase application filed under 35U.S.C. § 371 of International Application No. PCT/AT2015/000115, filedSep. 1, 2015, designating the United States, and claims priority fromAustrian Patent Application No. A 669/2014, filed Sep. 1, 2014, and thecomplete disclosures of which applications are hereby incorporatedherein by reference in their entirety for all purposes.

FIELD OF THE INVENTION AND TECHNOLOGICAL BACKGROUND

The invention relates to a control device of a transmission ratiobetween a traction means and a wheel set rotatable about a wheel axleand including at least two wheel blades alternatively wrapped around bythe traction means, wherein at least one of the wheel blades is composedof several independently adjustable wheel rim segments, wherein theadjustment of the wheel rim segments in relation to a fixed plane(“plane of alignment”) in which the traction means wraps around thewheel set is effected by the control device in a direction substantiallytransverse to the plane of alignment, wherein the control devicecomprises at least one electrically actuatable control element, inparticular a actuator.

A control device of this type is, for instance, described in US2002/0084618 A1.

Various solution principles are known for actuating changeabletransmissions with wheel rim segments.

There, mechanical control elements each associated to a wheel rimsegment are moved one by one by running onto a stationary switch or rampso as to enforce their movements, and hence movement of the wheel rimsegments. Such control elements may, for instance, be designed aseccentrics moving the segment into and out of the operating range, or ofwedges causing such movement by axial displacement.

Likewise known are solutions in which the movements of all wheelsegments are simultaneously triggered by a central control devicerotationally decoupled from the stationary actuator. In those cases, thecontrol members are preloaded by an energy accumulator, in particular aspring element, and the wheel segments are prevented from theiradjustment movements until the correct shifting moment has been reached,whereupon the adjustment will take place under the action of the energyaccumulator.

Some solutions are based on the principle of temporarily moving thedivided, segmented or interrupted sprockets only during the shiftingoperation itself in order “to bring” the chain to the next-larger ornext-smaller diameter. Such solutions are, for instance, described inU.S. Pat. No. 4,127,038 or U.S. Pat. No. 4,580,997. There, the chain isbrought into alignment with the consecutive chain blade by pivoting inor axially moving the larger or smaller adjacent chain blade sector. Thealignment of the chain thus changes with a change of the transmissionratio.

CH 617 992 A5 discloses a principle by which the chain segments aregradually brought into alignment with the chain. The chain bladesegments are individually mounted on a corotating device by means ofpins. This enables a smaller construction. It will thus be basicallypossible to construct derailleur gears that provide the entire spectrumof transmission ratios on a single axis.

In all of the presently known principles, the adjustment of the wheelrim segments is accomplished by the mechanical power transmissionbetween a part of the control device corotating with the wheel rimsegments and a non-corotating part of the control device. Thenon-corotating part is, for instance, fastened to the bicycle frame andperforms an adjustment stroke that causes the adjustment of the wheelrim segments during the rotation by the appropriate cooperation with acorotating part of the control device. This involves the drawback ofcausing constant mechanical contact, and hence friction, during theoperation of the system. In addition to undesired stress and wear, thiswill also lead to the generation or noise and require the observance ofexact manufacturing tolerances and high adjustment expenditures duringassembling. Such principles are thus expensive in practice, renderingassembly difficult.

From the prior art, both manually operable control devices andelectrically operable control devices are known. An electricallyoperable control device for a transmission gear with segmented sprocketsis, for instance, described in US 2202/0084618 A1, which, however,involves the same drawbacks in terms of power transmission from astationary to a corotating part of the control device as explained abovein connection with manually operable control devices. Moreover, electriccontrol devices for conventional derailleur gears are known, yet alsothese have the disadvantage that a derailleur mounted to the stationarypart (e.g. bicycle frame) enforces a change of the traction mediumbetween the undivided wheel blades. Here too, an interface betweenrotating and stationary units is provided.

BRIEF DESCRIPTION OF THE INVENTION

It is, therefore, the object of the invention to overcome the initiallymentioned drawbacks, departing from the approach of using segmented,divided and/or interrupted sprockets. In particular, a control device ofthe initially mentioned kind is to be provided, which does not requireany stationary unit for the shifting operation.

To solve this object, it is provided according to the invention that theat least one control element is arranged to rotate with the at least twowheel blades.

By the use of electrically actuated control elements designed accordingto the invention for moving the sprocket segments, the drawbacks of theinitially mentioned approaches have been overcome. The mechanicalinterface between stationary and rotating units is omitted.Consequently, hitherto existing tolerance problems are obviated, whichmight lead to undesired contacts or shifting operations at movements ofthe rotating unit, and distortions caused by the drive, power or outputpower. Likewise, mounting expenditures are considerably reduced, sincethe whole device only comprises one independently functioning unit.Furthermore, the actuation of such units can be performed without theuse of rod assemblies or cables, which are subject to wear and bothtemperature and age-related changes in length. The otherwise existingrequirement for readjustment is therefore obviated.

In a preferred manner, it is provided that the at least one controlelement is arranged to effect a travel by closing an electric circuit,and thereby move at least one wheel rim segment, or a block thereof,into or out of its operating range.

Furthermore, it is preferably provided that a separate, corotating andelectrically actuatable control element is associated to each wheel rimsegment. This enables in a simple manner the separate actuation of theadjustment movement of each individual wheel rim segment.

The movement of the wheel rim segment caused by the electric actuatingelement can only occur in that region where the traction means is notpresent on the wheel rim segment, or must not be initiated where thefirst wheel rim segment has just passed the approaching traction medium.This requires the recognition of the region suitable for the adjustmentof the individual wheel rim segments. The wheel rim segments of a wheelblade in the control device architecture according to the invention arethus adjusted not all at the same time, but preferably one after theother. It is thus advantageous to provide a suitable actuation of theadjustment movement of the individual wheel rim segments. In aconfiguration in which a separate corotating control element isassociated to each of the wheel rim segments, such an actuation canpreferably be performed in that a sensor is associated to each controlelement, which sensor is arranged to interrogate the presence of thetraction means on a defined position and actuate the associated controlelement with a negative interrogation. Alternatively, this may happen inthat a sensor directly interrogates the presence of the traction mediumon the rotating unit itself so as to trigger the shifting operation ofthe associated wheel segment upon negative interrogation.

In view of the conversion of the actuating movement of the at least onecontrol element, such as the rotational movement of the control motor,into the adjustment movement of the individual wheel rim segments, knownmechanisms can be employed. In a preferred configuration, it is providedthat the at least one control element is connected to a threaded spindlein drive terms, wherein the spindle cooperates with a nut rotationallyfast with the respective wheel rim segment, in order to effect theactuation process by screwing the nut in or out.

Alternatively, it is provided that the at least one control element isconnected to a threaded spindle in drive terms, wherein the threadedspindle cooperates with a nut such that the wheel rim segments are movedinto or out of their operating range by respectively screwing in or outthe nut, which is connected to an eccentric.

In order to reduce the expenditures involved in the provision of anumber of control elements corresponding to the number of wheel rimsegments, a preferred configuration contemplates that a single controlelement is used, which is preferably arranged centrally, in particularin the region of the axis of rotation of the wheel blades. The centralcontrol element may, for instance, be arranged to perform a rotationabout the axis of rotation of the wheel blades or a linear movementalong the axis of rotation of the wheel blades.

In order to achieve a suitable sequential actuation of the adjustment ofthe individual wheel rim segments in a configuration comprising a singlecontrol element, it is preferably provided that the control elementcooperates with at least one energy accumulator, in particular a springelement, to charge or preload the same, wherein the charged energyaccumulator exerts an adjusting force on the at least one wheel rimsegment, the adjustment of the at least one wheel rim segment beingprevented until the wheel rim segment is in the non-wrapped-aroundregion of the traction means.

In this respect, it is preferably provided that a separate energyaccumulator, in particular a spring element, is associated to each wheelrim segment to cooperate with the centrally arranged, corotating,electrically driven control element for simultaneously charging theenergy accumulators of all wheel rim segments.

It is preferably provided that the centrally arranged control elementcooperates with the energy accumulators via a cam disc, said cam disccomprising a cam elevation for each of the energy accumulators.

In a preferred configuration, a central control element is provided,which is devised to drive a spindle of each individual wheel rim segmentvia a friction clutch so as to actually not move the same until theactuating movement has been enabled by a mechanical element. Themechanical element thus detects the presence of the traction means,allowing movement only when the traction means has left the region inquestion.

The control elements, on the one hand, may preferably be comprised ofcontrol motors, which accomplish the movement of the wheel rim segmentseither directly or via a lifting spindle, an eccentric or wedges, andblock the same in their operating positions such that the wheel rimsegments will be fixed in said positions following the adjustingoperation, until the control motor, or the lifting spindle, theeccentric or the wedge, respectively, will be moved again, thusreleasing the fixation.

On the other hand, the at least one control element may also becomprised of an electrically operated lifting magnet. The lifting magnetcauses the movement and fixation of the wheel rim segments eitherdirectly or via an eccentric or wedge.

In a particularly preferred manner, it is provided that the voltagesupply of the electric control elements is disposed on the rotatingunit. This will provide a closed system capable of being inserted intothe bicycle frame without interface and without any adjustment work. Onthe one hand, this will considerably reduce mounting expenditures and,on the other hand, this will prevent possible maladjustment of thecontrol mechanics so as to avoid readjustment and enable shifting alwaysat the optimum moment. This is of particular advantage in bicycles withspring-loaded chainstays, because the free part of the chain will changeby deflection. In particular, a corotating electronic control unit and avoltage supply are preferably provided.

Alternatively, it is provided that the at least one control element isconnected to a voltage supply via a slip ring contact. In this case, itis provided in a particularly preferred manner that the at least onecontrol element is actuated by the closing of a contact to thestationary voltage supply, which is caused in the rotating movement.

It is preferably provided that the control device is configured as anautonomously functioning unit capable of contactlessly receiving thecommand for actuating the corotating electric control elements. Theconfiguration in this case is preferably devised such that theelectronic control unit comprises a receiving circuit for receivingwirelessly transmitted control signals for the control device. Thewireless signal transmission of control commands for the at least onecontrol element may, in particular, be effected via radio transmission,wherein conventional transmission standards may be adopted. Thetransmitter device for transmitting the control signals may, forinstance, be incorporated in an actuation device attached to thehandlebars of a bicycle.

In a preferred manner, a sensor system is provided, which is arranged tomeasure the rotation speed and/or the driving force, and henceautomatically effect a gear change. The configuration in this case ispreferably devised such that a measuring device for detecting therotation speed and/or the driving force is provided, said measuringdevice cooperating with a control device for actuating the at least onecontrol element as a function of the detected rotation speed and/ordriving force, respectively. The control device according to theinvention thus is preferably configured as an automatic transmissioncomprising a suitable sensor system. When interrogating the speed andload, it is thus possible to effect an automatic gear change initiatedby the electronic system upon as a function of these parameters.

The control mechanism according to the invention is particularlysuitable for a gear shift in which the control mechanism is mounted to agear wheel, for instance a gear wheel that serves as a drive wheel of abicycle gearing.

However, the control elements according to the invention can also beused on a driven wheel, which in turn may constitute the drive wheel ofa vehicle, in particular bicycle.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, the invention along with further particulars andadvantages will be explained in more detail by way of non-limitingexemplary embodiments of the invention, which are illustrated in theaccompanying drawings. These show:

FIG. 1 illustrates a control mechanism comprising an undivided, smallsprocket and four pivotally mounted sprocket segments each including acontrol motor moving the sprocket segments via a lifting spindle;

FIG. 2 is a front view of a control device according to a firstexemplary embodiment, comprising sensors interrogating the presence ofthe chain;

FIG. 3 depicts the control mechanism according to FIG. 1, comprising alifting magnet per sprocket segment, which directly moves the latter andis supplied and actuated via a corotating control unit and voltagesupply without connection to the stationary unit;

FIG. 4 is a front view of the control mechanism according to FIG. 3;

FIG. 5 depicts a control mechanism according to FIG. 1, comprising alifting magnet per sprocket segment to move the latter via an eccentriclever;

FIG. 6 depicts a control mechanism according to FIG. 1, comprising asingle central, annular lifting magnet disposed about the shaft andmoving the sprocket segments each via an eccentric lever;

FIG. 7 depicts a control mechanism according to FIG. 1, comprising asingle central, annular lifting magnet disposed about the shaft andmoving the sprocket segments via a cam disc and an eccentric lever each;

FIG. 8 illustrates the control mechanism of FIG. 7 in front view;

FIG. 9 depicts a control mechanism according to FIG. 1, comprising asingle central, annular control motor disposed about the shaft andmoving the sprocket segments via friction wheels; and

FIG. 10 is a front view of the control mechanism according to FIG. 9.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTION

A first aspect of the invention avoids contact, as far as possible,between stationary and rotating units in that the mechanical system on astationary point, which performs the displacement of the sectored,divided or interrupted sprockets, is omitted. The control mechanism inFIG. 1 shows wheel rim segments 1, which are moved into and out of theirrange of operation by rotating a spindle 2. The rotational movement iseffected by switching on and off, or changing the direction of, acontrol motor 3 per wheel rim segment 1, which is supported on a fixedpart, i.e. the small and undivided sprocket 4 in the present case. Theassociated control motor 3 is energized when contact to the stationaryvoltage supply has been established by the rotational movement.

FIG. 2 depicts a configuration according to FIG. 1, yet a sensor 5 percontrol motor 3, which interrogates the presence of the chain 6, isattached in such a manner that the control movement, or power-up of thecontrol motor 3, or beginning of the adjusting operation of the wheelrim segment 1, will start at the right moment, so that the wheel rimsegment 1 is adjusted only when it is in the non-wrapped-around regionof the traction means 6.

FIG. 3 illustrates a preferred embodiment comprising a lifting magnet 7for each wheel rim segment 1, which moves the wheel rim segment 1directly into and out of its operating position. A corotating voltagesupply 8 and electronics 9 are contactlessly actuated via radio 10 by atransmitter 11. A sensor 5 interrogates the presence of the tractionmeans 6, and the adjusting operation per wheel rim segment 1 isaccomplished at the appropriate time during rotation, when the wheel rimsegment 1 is in the non-wrapped-around region of the traction means 6.

FIG. 4 depicts the front view of FIG. 3.

FIG. 5 illustrates an embodiment comprising sprocket segments 1, whichare forced to movement by a lifting magnet 7 via a lever 12. Thisembodiment enables the use of a lifting magnet 7 which, not energized inits end position, has no power to fix the wheel rim segment 1, sinceself-locking occurs due to an advantageous shape of curve. Therespective wheel rim segment 1 will thus be fixed in its respective endposition.

FIG. 6 illustrates an embodiment comprising a central annular liftingmagnet 7 disposed about the axis of rotation and actuating a tappet 14per wheel rim segment 1 via a wedge-shaped ring 13 by changing positionbetween two axial end positions, which tappet will, in turn, not performthe movement of the lever 12 via an intermediate spring accumulator 15before the chain 6 has left the small sprocket.

FIG. 7 illustrates an embodiment according to FIG. 6, yet the tappets 14are actuated by a control motor 3 disposed centrally about the shaft andvia a cam disc 16. The mechanical interrogation of the presence of thechain 6 in this case is accomplished by a protrusion on the lever 12.

FIG. 8 is a front view of the arrangement according to FIG. 7.

FIG. 9 illustrates an embodiment comprising a central control motor 3driving a first friction wheel 17, which in turn drives a secondfriction wheel 18 in a frictionally engaged manner, which secondfriction wheel, while connected to a spindle 2, moves the sprocketsegment 1. The cam disc 16 prevents the second friction wheel 18 frommoving, and hence adjusting the wheel rim segment 1, until the chain 6has left the region of the small sprocket.

FIG. 10 is a front view of the arrangement according to FIG. 9.

It goes without saying that the aspects and embodiments of the inventionshown and described herein, and their particulars, can be combined withone another.

The invention claimed is:
 1. A control device of a transmission ratiobetween a traction means and a wheel set rotatable about a wheel axleand including at least two wheel blades alternatively wrapped around bythe traction means, wherein at least one of the wheel blades is composedof several independently adjustable wheel rim segments, wherein thecontrol device comprises at least one electrically actuatable controlelement characterized in that the at least one control element isarranged to rotate with the at least two wheel blades, and wherein thecontrol device effects adjustment of the wheel rim segments in relationto a fixed plane, which fixed plane defines a plane of alignment, inwhich the traction means wraps around the wheel set in a directionsubstantially transverse to the plane of alignment.
 2. A control deviceaccording to claim 1, wherein the at least one control element isarranged to effect a travel by closing an electric circuit, and therebymove at least one wheel rim segment, or a block thereof, into or out ofits operating range.
 3. A control device according to claim 1, wherein aseparate, corotating and electrically actuatable control element iscoupled to each wheel rim segment.
 4. A control device according toclaim 1, wherein the control device further comprises a sensor isassociated to each control element, which sensor is arranged tointerrogate the presence of the traction means on a defined position andactuate the associated control element with a negative interrogation. 5.A control device according to claim 1, wherein the at least one controlelement is connected to a threaded spindle in drive terms, wherein thespindle cooperates with a nut rotationally fast with the respectivewheel rim segment, in order to effect the actuation process by screwingthe nut in or out.
 6. A control device according to claim 1, wherein theat least one control element is connected to a threaded spindle in driveterms, wherein the threaded spindle cooperates with a nut such that thewheel rim segments are moved into or out of their operating range byrespectively screwing in or out the nut, which is connected to aneccentric.
 7. A control device according to claim 1, wherein the controldevice further comprises at least one energy accumulator and the atleast one control element cooperates with the at least one energyaccumulator to charge or preload the same, wherein the charged energyaccumulator exerts an adjusting force on the at least one wheel rimsegment, the adjustment of the at least one wheel rim segment beingprevented until the wheel rim segment is in the non-wrapped-aroundregion of the traction means.
 8. A control device according to claim 7,wherein each energy accumulator is associated to each wheel rim segmentto cooperate with a centrally arranged, corotating, electrically drivencontrol element for simultaneously charging the energy accumulators ofall wheel rim segments.
 9. A control device according to claim 8,wherein the centrally arranged control element cooperates with theenergy accumulators via a cam disc, the cam disc comprising a camelevation for each of the energy accumulators.
 10. A control deviceaccording to claim 1, wherein the control device includes a centralcontrol element, which is devised to drive a spindle of the individualwheel rim segments via a friction clutch so as to actually not move thesame until the actuating movement has been enabled by a mechanicalelement.
 11. A control device according to claim 1, wherein the at leastone control element is comprised of an electrically operated liftingmagnet.
 12. A control device according to claim 1, wherein the at leastone control element is connected to a non-corotating voltage supply viaa slip ring contact.
 13. A control device according to claim 1, whereinthe at least one control element is actuated by the closing of a contactto a stationary voltage supply, which is caused in the rotatingmovement.
 14. A control device according to claim 1, wherein the controldevice further comprises a corotating electronic control unit foractuating the at least one control element, and an optionally corotatingvoltage supply for the at least one control element.
 15. A controldevice according to claim 14, wherein the corotating electronic controlunit comprises a receiving circuit for receiving wirelessly transmittedcontrol signals for the control device.
 16. A control device accordingto claim 1, wherein the control device further comprises a measuringdevice for detecting the rotation speed and/or the driving force, themeasuring device cooperating with a control device for actuating the atleast one control element as a function of the detected rotation speedand/or driving force, respectively.
 17. A control device according toclaim 1, wherein the at least one electrically actuatable controlelement comprises a servomotor.
 18. A control device according to claim7, wherein the at least one energy accumulator comprises a springelement.